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Post by redog on Mar 24, 2015 13:35:57 GMT -5
So has anyone ever burned in their speakers, and they sounded worse afterwords?
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Post by 405x5 on Mar 24, 2015 14:20:27 GMT -5
If new speakers sound "worse" after a period of initial use, you have a problem or defect of some kind. Could be any number of things from a cold solder joint to a voice coil rub, etc. There is no such thing as speaker burn in or break-in. If all is good, they should perform to spec. from day one. |
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KeithL
Administrator 
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Post by KeithL on Mar 24, 2015 16:28:53 GMT -5
I'd have to disagree with you there... burn-in is a real phenomenon with speakers. With all dynamic speakers, each cone or dome has suspension mechanisms. With most cone drivers, there are one or more suspension mechanisms that serve several purposes. The edge suspension keeps the cone from moving in any direction other than forward and backward, maintains the seal between the cone and the box, and applies spring force to return the cone to its rest position. A second flat suspension spring - called a spider - is attached further back and also guides the cone movement and applies spring force. With dome drivers, there may be a single edge mechanism that serves the same function as its counterpart on a cone. Each cone or dome has a characteristic called "resonance". The "free air resonance" is determined by the mass of the cone or dome and the amount of spring applied by the edge suspension and spider. The "box resonance" is related to that, and is determined by the mass and the combined springiness of the suspension in the speaker and of the air in the box. Both of these are important characteristics, and both the crossover and the cabinet must be designed to match the resonances of the drivers you're using. Now, in most real world speakers, the spider is made up of some sort of cloth with a stiffener added to it, and the edge suspension is made up of either some sort of rubber, some sort of high-strength foam, or formed cloth or cardboard... and all of these materials start out somewhat stiff, then get slightly softer and more flexible as they are flexed back and forth over time. Since these make up the "spring" that determines the resonance of the speaker, this means that the resonance of the speaker WILL change over time, which WILL change the sound of the speaker (whether slightly or a lot will depend on the rest of the design). In general, this value will change over the first few tens of hours, or even hundreds of hours, then stay relatively constant for the rest of the life of the speaker - and speaker designs are calculated using the "final" values. This means that, over the first few hours or tens of hours of play, a speaker WILL indeed often change its sound as it "burns in", and it may not sound exactly as it's supposed to for the first few hours. (This will happen by itself as you play music, and some people prefer to play test tones at a safe level for the first 12 hours or so to accelerate the process.) The amount of change that this burn in produces varies with different designs, and is easily measured, although it isn't usually drastic. A similar effect occurs with turntable cartridges, which also have springy suspension components that break in with wear, and similar minor changes occur with ribbon tweeters, planar and electrostatic speaker diaphragms, and headphones. Note that we're talking about measurable changes in the compliance of springy flexible materials (just like jeans and gloves get softer after you use them a while). I still suspect that most of what people believe to be burn-in is merely their getting used to the sound of a particular piece of equipment, and the changes I'm talking about, while measurable, may well not be very audible - but they are real. (You may also find that some manufacturers have already performed a 100 hour burn-in as part of their test procedures.) If new speakers sound "worse" after a period of initial use, you have a problem or defect of some kind. Could be any number of things from a cold solder joint to a voice coil rub, etc. There is no such thing as speaker burn in or break-in. If all is good, they should perform to spec. from day one. |
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Post by 405x5 on Mar 24, 2015 20:10:56 GMT -5
I'd have to disagree with you there... burn-in is a real phenomenon with speakers. With all dynamic speakers, each cone or dome has suspension mechanisms. With most cone drivers, there are one or more suspension mechanisms that serve several purposes. The edge suspension keeps the cone from moving in any direction other than forward and backward, maintains the seal between the cone and the box, and applies spring force to return the cone to its rest position. A second flat suspension spring - called a spider - is attached further back and also guides the cone movement and applies spring force. With dome drivers, there may be a single edge mechanism that serves the same function as its counterpart on a cone. Each cone or dome has a characteristic called "resonance". The "free air resonance" is determined by the mass of the cone or dome and the amount of spring applied by the edge suspension and spider. The "box resonance" is related to that, and is determined by the mass and the combined springiness of the suspension in the speaker and of the air in the box. Both of these are important characteristics, and both the crossover and the cabinet must be designed to match the resonances of the drivers you're using. Now, in most real world speakers, the spider is made up of some sort of cloth with a stiffener added to it, and the edge suspension is made up of either some sort of rubber, some sort of high-strength foam, or formed cloth or cardboard... and all of these materials start out somewhat stiff, then get slightly softer and more flexible as they are flexed back and forth over time. Since these make up the "spring" that determines the resonance of the speaker, this means that the resonance of the speaker WILL change over time, which WILL change the sound of the speaker (whether slightly or a lot will depend on the rest of the design). In general, this value will change over the first few tens of hours, or even hundreds of hours, then stay relatively constant for the rest of the life of the speaker - and speaker designs are calculated using the "final" values. This means that, over the first few hours or tens of hours of play, a speaker WILL indeed often change its sound as it "burns in", and it may not sound exactly as it's supposed to for the first few hours. (This will happen by itself as you play music, and some people prefer to play test tones at a safe level for the first 12 hours or so to accelerate the process.) The amount of change that this burn in produces varies with different designs, and is easily measured, although it isn't usually drastic. A similar effect occurs with turntable cartridges, which also have springy suspension components that break in with wear, and similar minor changes occur with ribbon tweeters, planar and electrostatic speaker diaphragms, and headphones. Note that we're talking about measurable changes in the compliance of springy flexible materials (just like jeans and gloves get softer after you use them a while). I still suspect that most of what people believe to be burn-in is merely their getting used to the sound of a particular piece of equipment, and the changes I'm talking about, while measurable, may well not be very audible - but they are real. (You may also find that some manufacturers have already performed a 100 hour burn-in as part of their test procedures.) If new speakers sound "worse" after a period of initial use, you have a problem or defect of some kind. Could be any number of things from a cold solder joint to a voice coil rub, etc. There is no such thing as speaker burn in or break-in. If all is good, they should perform to spec. from day one. Hi Keith,
Actually, I agree totally with what you have said here.......just want to go back for a moment to what was the original question:"
Posted by redog
6 hours ago
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So has anyone ever burned in their speakers, and they sounded worse afterwords?"
This I have not experienced since I got into this stuff back in the early 70's.
That to me is an indicator that something's up somewhere, either with his speakers, or something else. That being said, I agree of course at least that things change very notably over a period of time, particularly regarding surrounds and spiders. There is much focus these days on restoring woofers by replacing the foam surrounds, which usually handles the problem and yet, not enough attention gets paid to the spider which weakens over time and even if it's not torn and in tact, looses much of its compliance allowing the cone to bottom out with excessive excursion. Of course, the surround and the spider need to work together in order to control the woofers excursion. Recently, I had my set of (4) 10" woofers rebuilt with both spiders and surrounds in order to restore the nominal 1/2 inch excursion that was intended for their design. Interesting also, they are installed in the cabinets in a push/pull configuration (pictured in my avatar) the purpose being to reduce even order distortion.
Bill
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Post by plm on Mar 24, 2015 22:45:29 GMT -5
I usually use 100 hours of pink noise. Gets everything loosened up nicely, and if you have a mono pink noise source and invert one channel it's not too noisy as you get some acoustic cancellation. I just throw them in a spare room for those first few days.
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Post by deltadube on Mar 24, 2015 23:36:59 GMT -5
I usually use 100 hours of pink noise. Gets everything loosened up nicely, and if you have a mono pink noise source and invert one channel it's not too noisy as you get some acoustic cancellation. I just throw them in a spare room for those first few days. thanks sound like a bad way to break in speakers.. a variety of music would be better.. your at a small wave length spectrum limited.. cheers |
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Post by ceptorman on Mar 25, 2015 3:14:04 GMT -5
Klipsch recommends that you break a speaker in….http://www.klipsch.com/Education/breaking-in-speakers
How to: Breaking in speakers
Many audio experts and speaker manufacturers say that loudspeakers really benefit from break-in. Like anything else mechanical, the drivers—the midrange and woofers—found in almost all speakers have moving parts that move more freely with time, or effort. Two components may particularly benefit from a break-in period: The surround, which can be made of various types of rubber or foam, is what connects the edge of the cone to the speaker basket, and the spider, which connects the basket and the center of the cone.
Both surrounds and spiders are flexible; therefore, allowing them to experience their full range of motion and loosen up results in freer movement and better response. Think of it like stretching before you exercise.
There are several simple ways to break a speaker in; while you could choose to buy costly gear to do so, it really isn’t required.
The easiest—and most enjoyable—way is to simply play them, choosing music with a wide dynamic range. Playing it just a bit louder than you normally might also help. Many receivers have a test tone that can accomplish the same goal; test signals are also commercially available.
A small warning here: not all speakers will sound dramatically different after break-in. Some improve only marginally, while others do change in ways that may dazzle you. Either way, it’s possible that you’ll notice an improvement.
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Post by plm on Mar 25, 2015 10:03:12 GMT -5
I usually use 100 hours of pink noise. Gets everything loosened up nicely, and if you have a mono pink noise source and invert one channel it's not too noisy as you get some acoustic cancellation. I just throw them in a spare room for those first few days. thanks sound like a bad way to break in speakers.. a variety of music would be better.. your at a small wave length spectrum limited.. cheers What makes you think that? Pink noise covers all frequencies with a good octave-to-octave distribution. White noise would be unnecessarily tough on tweeters. |
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KeithL
Administrator
Posts: 9,958
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Post by KeithL on Mar 25, 2015 10:25:36 GMT -5
For anyone who found my response too long there (nah  ).... Some commercial speaker vendors burn in their speakers "completely" while others do not. Therefore, some commercial speakers do change the way they sound over the first hundred hours or so of use. However, since any competent designer will have designed their speakers based on the parameters of the speaker drivers after they've been burned in, if the sound does change, the speakers should sound "right" (the way the manufacturer intends) after they're burned in. Therefore, they shouldn't sound worse after burn in (unless you don't like the way the manufacturer made them sound). From my experience, the actual change in sound ranges from "slight" to "nonexistent"; I've never heard a speaker that sounded hugely different after burn in either way, so I'm still inclined to attribute MOST of what people hear more to their getting used to the sound of a new piece of equipment (especially since the sound of different speakers varies so much). However, this is important for DIYers - because it means that, if your design is critical of the performance parameters of your individual drivers, like if you're carefully tuning a bass reflex cabinet to the free air resonance of your driver, you should burn in the drivers before taking your final measurements or making any critical tweaks. (It's probably safe to assume that the specs on the spec sheet apply to a "burned in driver", and that a brand new driver may measure and perform somewhat differently.) While burn-in tends to affect drivers which have a significant range of motion more than those that don't move very far, and so affects woofers the most and tweeters the least, even tweeters may change their operating parameters a tiny bit. Also note that even non-dynamic speaker designs (like electrostatics and planars) do experience burn-in (the stretched diaphragm on an electrostatic or planar will "loosen up", which may change its resonant frequency, or even eliminate a resonance due to its initially being stretched especially tightly). Also, a brief note about HOW to burn in a speaker (and what to use). The goal of burn-in is NOT to "warm up the driver", but rather to mechanically move the moving parts back and forth to soften up flexible springy parts (like edge suspensions and spiders). However, you also need to be aware that most speakers cannot withstand high levels of power continuously for a long time (so don't put on a loud test tone and leave it running for hours or you may overheat your speaker and damage it). Therefore, if you're burning in a sub or woofer, the safest signal is going to be low frequency pink noise or a very low frequency test tone (because a low frequency will cause the driver to move a lot at relatively low power levels). For a full range speaker, music works just fine (you want the level to be high enough to "exercise" all the drivers but, again, keep the level reasonable). If your speakers are "portable", and you don't want to listen to them all night, you can put two speakers face to face, a few inches apart, and drape a blanket over the tops of both (and, if you connect them out of phase, there will be even less sound escaping  ). I'm inclined to believe that "overnight" is plenty of time to burn in a speaker. (Personally, I usually don't bother, unless I'm comparing speakers or testing them, since they're going to "get burned in" when you listen to them anyway.... ) Incidentally, this is usually a "one-way" process (speakers don't get "un-burned-in" if they sit unused for a few months)... although the suspension on some speakers - especially older ones using older suspension materials - may stiffen up and change after a long period of time (years). Hi Keith,
Actually, I agree totally with what you have said here.......just want to go back for a moment to what was the original question:"
Posted by redog
6 hours ago
.
So has anyone ever burned in their speakers, and they sounded worse afterwords?"
This I have not experienced since I got into this stuff back in the early 70's.
That to me is an indicator that something's up somewhere, either with his speakers, or something else. That being said, I agree of course at least that things change very notably over a period of time, particularly regarding surrounds and spiders. There is much focus these days on restoring woofers by replacing the foam surrounds, which usually handles the problem and yet, not enough attention gets paid to the spider which weakens over time and even if it's not torn and in tact, looses much of its compliance allowing the cone to bottom out with excessive excursion. Of course, the surround and the spider need to work together in order to control the woofers excursion. Recently, I had my set of (4) 10" woofers rebuilt with both spiders and surrounds in order to restore the nominal 1/2 inch excursion that was intended for their design. Interesting also, they are installed in the cabinets in a push/pull configuration (pictured in my avatar) the purpose being to reduce even order distortion.
Bill
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Post by deltadube on Mar 25, 2015 11:58:22 GMT -5
thanks sound like a bad way to break in speakers.. a variety of music would be better.. your at a small wave length spectrum limited.. cheers What makes you think that? Pink noise covers all frequencies with a good octave-to-octave distribution. White noise would be unnecessarily tough on tweeters.  I think playing music is better.. cheers |
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Post by 405x5 on Mar 25, 2015 19:18:16 GMT -5
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Post by ceptorman on Mar 25, 2015 21:28:43 GMT -5
^^Haha^^ That's pretty cool!
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Post by 405x5 on Mar 26, 2015 9:43:39 GMT -5
^^Haha^^ That's pretty cool! Yes.....sometimes, a touch of "redneck relief humor" helps to keep things in perspective! |
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)....
). I'm inclined to believe that "overnight" is plenty of time to burn in a speaker. (Personally, I usually don't bother, unless I'm comparing speakers or testing them, since they're going to "get burned in" when you listen to them anyway.... )
